Allosaurus, meaning “different lizard” was one of the species cloned by InGen and present on Isla Nublar. Allosaurus was a theropod dinosaur from the Late Jurassic period (155 to 150 million years ago) of North America with material that has been found in Portugal and Tanzania indicating this animal was widely dispersed animal across the globe. Allosaurus was approximately 28 feet (8.5 meters) in length with some specimens growing upwards of 39 feet (12 meters) in length. It was the top predator of its day and lived along side dinosaurs such as Stegosaurus, Brachiosaurus, Apatosaurus, Camarasaurus, and Ceratosaurus.
The Allosaurus most likely inhabited the restricted zone on Isla Nublar up until the 2015 incident involving the Indominus Rex, and subsequent shut down of the Jurassic World resort. One was briefly seen during the eruption of Mount Sibo as Claire Dearing and Franklin Webb attempted to escape the blast wave of the volcano’s eruption inside the Gyrosphere. However, it was then likely killed by the blast radius of a large piece of volcanic debris, landing right beside the animal a few moments later. Another “juvenile” specimen was later seen being auctioned off by Gunnar Eversoll at the Lockwood Estate as part of the animals captured by Eli Mills and Ken Wheatley. It or another specimen was later seen again being transported inside one of a convoy of trucks traveling though Monument Valley, Utah.
Approximately one year after the eruption of Mount Sibo and dinosaurs being released from the failed auction of them at the Lockwood estate onto the continental United States mainland in California, an Allosaurus is seen at Big Rock National Park fighting with a Nasutoceratops mother and baby. As the Allosaurus lunges for the baby multiple times and tries to engage the mother a second Nasutoceratops arrives on the scene, presumably the male, to chase it off. The battle is lost thanks to the timely arrival of the animal’s mate. Before the Allosaurus can leave though it is distracted by a child’s cries from a family watching in a camper. Due to the crying of the infant, the Allosaurus decides to prey upon the family after it’s unsuccessful hunt with the Nasutoceratops. After a horrendous confrontation the animal is eventually scared off after two bolts from a crossbow blind it in one eye by the family’s 8-year-old daughter, Kadasha. The Allosaurus runs off into the forest while the family counts their blessings they survived the ordeal at the camp ground.